Composition of matter, etc.



Patented Dec. 11, 1934 r I UNITED STATES, PATENT OFFICE.

J 7 1,934,173, p I COMPOSITION OF MATTER, ETC; Charles H. Champion, New fork, N. 1., assignor I j 'to R. T; Vanderbilt 00., Inc., New York, g

a corporation of New Yor I NoDrawing. Application May 13, 1931:, Serial No 537,205. Renewed October 25,1934 v 2 Claims. (01.134-18) This invention relates to a new composition of The proportions, of calcium carbonate, lime, matter and to improved methods of using the and alum used in making the: new composition same for coating, filling, and other purposes. can be varied. In general the calcium carbonate Thenew composition is a dry mixture containwillbepresent in preponderatmg amount, andfor 5 ing alum, lime, and calcium carbonate, with the certain purposes, such as used in filling paper, the 5.

calcium carbonate predominating in amount in calcium carbonate forms from'about '75 to 90% most cases, and with the lime'and alum in varyby weightof the dry mixture. The proportions ing proportions. The composition is prepared by of alum and lime to each other can also be varied, mixing the materials dry to obtain an intimate for example, from about equal proportionsto, an 10 and uniform admixture. amount of alum which is as much as about four l0.

When the dry composition is added to water, or'five times the Weight of the lime. the lime and alum will react in the presence of The. proportions of alumand'limecan'be varied the calcium carbonate to form a reaction mixover a muohwid r ransainthe new dry mixture ture or composition containing the calcium car-.- of the present i vention, than is p bl With bonate distributed in and suspended in the reac-. mixtures of lime and alum when these two mal5 tion products of the limeandalum. 'The reaction terials ar caused to. act with each other in mixture thus produced is a valuable material as. the a s nc i ali carbonataand where the a filling material for paper or textiles or for coat: propor ions pp oximate equal proportions of ing paper or textiles, etc. and for various other um and me. I have found that the alumcan purposes such as a cold water paint composition. ei i r ased as much as. four or .five timesthe After drying, the reaction mixture is a valuable wei ht Of the lime. when calcium carbonate is material for compounding with rubber or in makadmixed th rew thand that herresultin d y ing oil paints, etc. 7 mix ure s a valuab e omposition for use in Calcium carbonate is extensively used as a paper mil as a fi lin fo paper. Such a dry filling materiahfor example, for filling and coatmix ure. whe a ed to. Water, will undergo re- 25 ing paper, but it does not readily stay in sus cti n form a suspension f t alcium oarpension and readily settles out when an opp0rbonate in h react n productsof the lime and tunity is given for it to do so. Itis also known a m, Wh G u nsi n and reacti p oducts that lime and alum will react together, in cera valua l filling mate ials f r thefilling of tain proportions, to give areaction product which pap r. A advanta e us p Oportion of ingredi- 30 can be used for certain purposes, such as the coat-. rits for this purpose is about 8,. by weight of ing of paper. To some extent also, calcium carca cium carbonat abou %.of alum and about bonate has been used in admixture with such 0 1. -11. (hy rated). 1'1 previously prepared reaction products of alum I The cal um b nate empl yed is p p ated and lime in the coating of paper. ca ium carbona e u has is obtainable by the I have found that improved results in the c0atoarbonatins of m lk O m or as a lay-product ing of paper, and also in the filling of paper, can rom he au ticizins Qf Sodium carbonate solube obtained by admixing the lime and alum dry tion. th m lk 9 l m For most purposes it with calcium carbonate, in proper proportions, h l be f e rom i yadmixtures which can and adding the resulting dry mixture to water so be readily separated from the'milk of .lime be- 40 that the reaction between the lime and alum takes fore carbonating or before using it for causticizplace in the presence of the calcium carbonate ins.- The precipitated calcium carbonate will be to form a reaction product in which the calcium driedand reduced to a finely divided state, so that, carbonate is suspended in and surrounded by the or xamplathe greater part of it will pass reaction product. The admixture of the dry inthrough a 200 mesh screen, although the fineness gredients, and the addition. of the dry mixture of the calcium carbonate .canbe varied-somewhat to water, makes unnecessary the sepa ate pr d p n ing upon the purp fo whi h p liminary reaction of lime with alum and the .dry- Sition is to be used;and a more finely divided p ing of the reaction product before shipment and not can be used when desired. use, and ives a reaction product in which the The lime employed in the new composition is 50 calcium carbonate is suspended in and surroundhydrated lime freed from objectionable admixed by the reaction product in a manner not ,obtu-res of gritty or foreign materials and in a suittainable where the reaction product is first pre ably dried and finely divided state so that it can pared and dried and subsequently admixed with b admixed with the calcium carbonate and alum the calcium carbonate. to form a uniform admixture. The alum used is the ordinary alum of commerce in a finely divided state.

In the filling of paper it is customary to add clay to the beater so that it will be incorporated in the paper when the pulp, after beating and subsequent dilution, is formed into a sheet of paper on the paper machine; but substantial losses of clay as well as of other constituents including pulp fibers frequently occur in the white water or waste water from the paper making operation. The new dry composition, when added to the beater, or when first added to water and caused to react and the resulting reaction mixture is added to the beater, forms a valuable substitute for clay as afiller and appears to have a coagulating efiect on the water in which the pulp is suspended so that losses in the white water or Waste water are minimized. When used for filling paper the calcium carbonate will in general form from around '75 to 90% of the dry mixture and the lime and alum together from about 25 to 10% of the mixture. The proportions of alum to lime can vary, for example, from around equal proportions up to around one and a half times as much alum as lime and even up to as much as four or five times as much alum as lime; and the higher proportions of alum to lime are particularly advantageous in paper mill operations where the dry mixture is added to the furnish or first caused to react with water and then added to the beater.

Instead of using a high proportion of alum. to lime in the dry mixture, a lower proportion can be used, particularly where alum is separately added to the pulp in the paper mill. The alum previously added and present in the water will react with the added ingredients of the dry mix or with the reaction product of the dry mix when it is added to water and caused to react before adding it to pulp.

The reaction products resulting from the reaction of alum and lime in the presence of water are more or less colloidal in character and the reaction products are more or less gelatinous and voluminous. When the reaction takes place in the presence of calcium carbonate uniformly distributed throughout the mixture, the calcium carbonate is suspended in the reaction products, but the presence of the calcium carbonate results in an apparent tendency toward agglomeration of the reaction products. For example, when the dry reaction mixture containing calcium carbonate is caused to react in water and the reaction product is permitted to settle, thevolume is considerably less than the volume of the reaction product between alum and lime alone after being permitted to settle; but the volume is far greater than that of the calcium carbonate by itself. When the reaction product is formed in the paper pulp, by adding the dry mixture to the paper pulp, or when the reaction is caused to take place in the presence of a limited amount of water and the resulting reaction mixture containing the reaction product in suspension in water is added to the pulp, the individual particles of calcium carbonate suspended in the reaction products of the lime and alum are readily incorporated with the fibers when the pulp, after beating, is diluted with water and forms into paper on the paper machine.

. For the coating of paper, the same proportions of the ingredients of the dry mixture may be employed as for filling paper, and such a mixture forms a valuable substitute for clay fillers. Where a lighter colored material is desired, less calcium carbonate can be used and an increased proportion of the alum and lime. So also, the proportions of alum and lime, for making a coating material, may approximate more closely to equal proportions, without using such a large excess of alum as is desirable for filling material. By varying the proportions of lime and alum, the gloss desired on the finished coated paper can be varied; for example, using equal parts of lime and alum will produce a high gloss sheet, whereas using three parts of alum to one of lime will produce a low gloss sheet. In applying the new com position for coating paper, the dry mixture is added to water and the reaction is permitted to take place and the resulting suspension is then added to a solution or suspension of other ingredients, such as a solution of casein or glue in alkali. In general the reaction products produced from the dry mixture, on reaction in water, can be used much as clay is used in coating paper; but where smaller proportions of calcium carbonate are present in the dry mixture, the dry mixture can be used to replace not only part of the clay or all of the clay, but also part or all of the previously prepared reaction products of alum and lime by themselves, which reaction products are now employed in a previously prepared form for certain grades of coated paper.

The amounts of the new composition used for filling or coating paper can be varied, depending upon the results desired. Even where high percentages of filler are desired, the new composition enables such percentages to be obtained without excessive loss in the waste water. When it is considered that for each thousand pounds of pulp (dry weight) in a beater there are around twentyfour thousand pounds of water, and that this stock is later diluted, after beating, with around eight to ten parts of water for each part of stock, it will be appreciated that there is a large volume of water to be separated from the pulp during the paper making operation, and that the loss of even small percentages of clay or other filler in the waste water involves an important loss in the aggregate. The reaction product resulting from the use of the dry mixture of the present invention, because of its colloidal or gelatinous character, and because the calcium carbonate is suspended in such colloidal or gelatinous reaction product, is of such a character that not only are losses of the filling material itself minimized, but losses of the pulp itself are minimized.

The new dry composition, after reacting in water, can be used for the coating or filling of other materials than paper, for example, for filling textile materials or fabrics of various kinds. The reaction product can be dried and the dried product ground and used as a pigment or filler for various purposes such as rubber, oil paints, etc. The reaction product itself, without drying, and properly diluted with water, and with other admixtures if desired, can be used directly as a cold water paint or for other purposes.

It will thus be seen that the present invention provides a dry composition which can be readily manufactured and shipped and stored and which is adapted for use either in a dry state by adding to paper pulp or by first adding it to water and permitting thereaction to take place after which the reaction mixture can be added to the paper pulp, or used for other purposes, such as those above referred to. The new composition thus referred to facilitates the filling of paper, requiring merely that the proper amount of dry mixture be added to the paper pulp or first added to water and the reaction mixture then added to the pulp. It will also be seen that the composition provides not only an improved substitute for clay fillers, but a filling composition which has distinct advantages. Whereas calcium carbonate alone, when used as a filler, gives a harsh paper, the use of the new composition overcomes the harshness and gives a soft filled paper.

While I have described the new composition as being made up of calcium carbonate, alum and lime, I do not exclude the presence of other constituents which do not interfere with the desired reaction and suspension of the calcium carbonate in the reaction product, or which supplement and modify these ingredients.

I claim:

1. A new composition consisting of a dry mixture of calcium carbonate, alum and lime, all in a finely divided state, the calcium carbonate being present in preponderating amount, the amount of alum being insufiicient to react with all of the calcium carbonate and the proportion of alum to lime varying from about equal proportions to about five times as much alum as lime or more, said dry composition being adapted to be shipped and stored and used in predetermined amounts with water, with resulting reaction of the alum and lime in the presence of the calcium carbonate to form a reaction mixture containing the calcium carbonate in suspension in the reaction products of the alum and lime.

2. A new composition consisting of a dry mixture of calcium carbonate, alum and lime, all in a finely divided state, the calcium carbonate forming about '75 to 90 by weight of the dry mix ture, the amount of alum being insufiicient to react with all of the calcium carbonate and the ratio of alum to lime varying from about 1 to 1 up to about 5 to 1, said dry composition being adapted to be shipped and stored in a dry state and used by addition of water with resulting reaction of the alum and lime in the presence of the calcium carbonate to form a reaction mixture containing the calcium carbonate in suspension in the reaction products of the alum and lime.

CHARLES H. CHAMPION. 

